Fill a large stock pot with water and add the potatoes and 1 tablespoon kosher salt. Cover partially with a lid and bring to a boil over. Cook the potatoes until you can easily pierce their centers with a fork, around 30 minutes. Drain the water and let the potatoes cool slightly. Peel the skin and return back to the pot.

In a small saucepan, combine the chicken stock, thyme and butter. Set over medium heat and bring to a gentle simmer, stirring constantly to emulsify the butter, around 5 minutes.

Add the hot stock and olive oil to the potatoes and mash with a potato masher until smooth. For a creamier finished product, you can first pass the potatoes through a potato ricer and/or use a hand mixer to beat the potatoes until fluffy.

Taste the potatoes for seasoning and adjust with salt as desired. Transfer to a serving bowl and drizzle with more olive oil. Serve immediately or cover and keep in a warm oven until ready to serve.